title: Operational strategies for nitrogen removal in granular sequencing batch reactor.
abstract: This study investigated the effects of different operational strategies for nitrogen removal by aerobic granules with mean granule sizes of 1.5mm and 0.7 mm in a sequencing batch reactor (SBR). With an alternating anoxic/oxic (AO) operation mode without control of dissolve oxygen (DO), the granular sludge with different size achieved the total inorganic nitrogen (TIN) removal efficiencies of 67.8-71.5%. While under the AO condition with DO controlled at 2mg/l at the oxic phase, the TIN removal efficiency was improved up to 75.0-80.4%. A novel operational strategy of alternating anoxic/oxic combined with the step-feeding mode was developed for nitrogen removal by aerobic granules. It was found that nitrogen removal efficiencies could be further improved to 93.0-95.9% with the novel strategy. Obviously, the alternating anoxic/oxic strategy combined with step-feeding is the optimal way for TIN removal by granular sludge, which is independent of granule size.
authors.affiliation: College of Environmental Science and Engineering, Kunming University of Science and Technology, 282 Xuefu Road, Kunming 650093, PR China.
authors.forename: Fang-yuan
authors.initials: FY
authors.lastname: Chen
authors.forename: Yong-Qiang
authors.initials: YQ
authors.lastname: Liu
authors.forename: Joo-Hwa
authors.initials: JH
authors.lastname: Tay
authors.forename: Ping
authors.initials: P
authors.lastname: Ning
mesh_terms: D000332:Aerobiosis; D001673:Biodegradation, Environmental; D019149:Bioreactors; D000860:Hypoxia; D009584:Nitrogen / Q000302:isolation & purification / Q000378:metabolism*; D012722:Sewage / Q000382:microbiology*
chemical_list: D012722:Sewage; D009584:Nitrogen